Compare AI models

Specifications
Context window
1M—
API pricing
Input price
$10.00$2.50
Output price
$50.00$15.00
Cached input price
$0.25$0.25
Cheapest input
$10.00Amazon Bedrock$1.25OpenAI
Cheapest output
$50.00Amazon Bedrock$7.50OpenAI
Benchmarks
BullshitBench v2
77%48%
Next.js Evals
97%65%
Humanity's Last Exam · with tools
65.6%52.1%
ARC-AGI-2
90%73.95%
Overview
CompanyAnthropicOpenAI
Release dateSep 1 2026Mar 5 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Fable 5.1 leads GPT-5.4 on 4 of the 4 benchmarks they both report (BullshitBench v2, Next.js Evals, Humanity's Last Exam, ARC-AGI-2). GPT-5.4 is cheaper on both input and output: $2.50 vs $10.00 per million input tokens, and $15.00 vs $50.00 per million output tokens. GPT-5.4 shipped 180 days before Claude Fable 5.1, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

On BullshitBench v2, Claude Fable 5.1 leads at 77% vs GPT-5.4 at 48%. On Next.js Evals, Claude Fable 5.1 leads at 97% vs GPT-5.4 at 65%. On Humanity's Last Exam · with tools, Claude Fable 5.1 leads at 65.6% vs GPT-5.4 at 52.1%. On ARC-AGI-2, Claude Fable 5.1 leads at 90% vs GPT-5.4 at 73.95%.